What is your longest surviving work?

(What design of yours is still used in production years after you've shipped it?)

a decade+ of consumer products | decentralized analytics: /intelligent | self exploration: /tanishq

built a location service at my previous job thats 4+ years old and still being actively developed which is pretty rare in the age of rewrites and migration

Risk @Stripe prev: wallets @bitski, search @airbnb | https://www.castsense.xyz/ 

Oh, that's indeed very surprising considering such services upgrade so damn fast!